Life and death of Crocosphaera sp. in the Pacific Ocean: Fine scale predator-prey dynamics
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Non |
| Statut de publication | : | Publié |
| Année de publication | : | 2020 |
| Auteurs (5) | : | DUGENNE Mathilde FREITAS Fernanda,henderikx WILSON Samuel,t KARL D,m WHITE Angelicque,e |
| Revue scientifique | : | Limnology And Oceanography |
| Volume | : | 65 |
| Fascicule | : | 11 |
| Pages | : | 2603-2617 |
| DOI | : | 10.1002/lno.11473 |
| URL | : | - |
| Abstract | : | In the North Pacific Subtropical Gyre, the daily pulse of photosynthetic carbon (C) fixation is closely balanced by losses. This concert of growth and loss is driven by a diverse assemblage of plankton, including the diazotrophCrocosphaerasp. While primary production is relatively well characterized in this ecosystem, the extent of C transfer to secondary producers is poorly constrained. Here, we use automated imaging flow cytometry and population modeling to study the coupling of C production byCrocosphaeraand subsequent grazing by nanoplanktonic protists.Crocosphaeracells represent on average 30% of the nanoplankton detected by the Imaging FlowCytoBot in the surface layer of mesoscale eddies during summertime. The size spectra show a maximum in the frequency ofCrocosphaeradoublet cells just prior to mitotic division at midday, with an average estimated growth rate of 0.8 +/- 0.5 d(-1). We also identified potential predators by fitting a Lotka-Volterra model to plankton time series observations. Significant predators include the dinoflagellatesProtoperidiniumandDinophysisas well as the ciliateStrombidium, which were all imaged withCrocosphaerain food vacuoles. The estimated C demand of the main grazers fluctuated between 25% and 250% ofCrocosphaeranew production in an anticyclonic eddy where we observed the onset of aCrocosphaera-driven bloom. HeterotrophicProtoperidiniumdrove most of the estimated C demand, with grazing rates nearly equivalent toCrocosphaeragrowth rates (0.6 +/- 0.4 d(-1)on average), but saturating at high prey concentrations. Our novel results demonstrate tight coupling between specific protistan predators and a diazotrophic prey. |
| Mots-clés | : | - |
| Commentaire | : | - |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Dugenne M, Freitas FH, Wilson ST, Karl DM, White AE (2020) Life and death of Crocosphaera sp. in the Pacific Ocean: Fine scale predator-prey dynamics. Limnol Oceanogr 65: 2603-2617 | doi: 10.1002/lno.11473
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